Tree · Pinaceae
White Fir
Abies concolor
Give it room, sun, and well-drained acidic soil, and the white fir will reward you with its silvery-blue pyramid for generations.
Full sun
Every 7–14 days
USDA 3–7
30–70 ft · 9.1–21.3 m
Overview
White fir is a true fir from the mountains of the western United States, and it has won gardeners over far beyond its native range. You will love its neat pyramidal shape and the soft blue-green to silvery-blue needles that set it apart from spruce and pine. Grow it kindly and it will stand for a very long time, since this is a slow, long-lived perennial evergreen.
Of all the firs people plant, this is one of the most forgiving, which makes it a comforting choice if you are new to trees. It takes cold down to -40°F (-40°C), copes with heat better than most of its kin, and puts up with city air and clay where fussier firs would sulk. The one thing it cannot abide is wet feet, so good drainage is what decides whether your tree thrives or rots.
Most folks grow the straight species, though a few blue-needled selections push the color even further. Whichever you pick, do plan around its size. This tree gets big, so the kindest thing you can do is give it the right spot from the very start.
Care
The short version: give it full sun, deep and acidic well-drained soil, and steady moisture while it settles in. After that it asks for very little beyond room to grow, and the only thing it truly cannot forgive is a wet, heavy site.
Light
Give your white fir full sun for the densest, best-colored growth. It will take partial shade and still do nicely, but a tree out in the open holds its tidy pyramid and its silvery-blue tone so much better.
Water
Offer the tree deep, regular watering while it establishes and through any drought, since it likes soil that stays evenly moist. Let the top half of the root zone dry between drinks, and never leave it standing in wet ground, which is the quickest road to root rot.
Soil
This fir wants rich, deep, acidic soil that drains freely, whether sandy or loamy. A pH from 5.0 to 7.0 suits it well, while heavy compacted clay or a low wet spot will slowly do it in.
Temperature
Few garden trees are as tough in the cold. White fir takes winters down to -40°F (-40°C) and summers up to about 95°F (35°C), which is why it sails through climates that would defeat softer firs.
Humidity
Ordinary outdoor air suits it perfectly, so there is no number to chase. Among the western firs, this one copes best with dry heat and the humidity swings of the wider garden.
Feeding
An established white fir in decent ground rarely needs feeding, so you can mostly set this worry aside. Reach for a balanced or acidifying tree fertilizer in spring only when a soil test points to a real shortage, never out of habit.
Pruning
Mostly, leave the tree to itself. Take out dead, damaged, or crossing branches in late winter, and protect the central leader so the tree keeps its natural pyramid.
Repotting
none
Size & spacing
White fir is a forest tree at heart, reaching 30 to 70 feet (9 to 21 meters) tall with a spread of 15 to 30 feet (4.5 to 9 meters), and taller still in the wild. Give it that full footprint and set it well clear of buildings and power lines, and the two of you will get along for decades.
When to plant
You plant white fir rather than sow it, and the timing could not be simpler. Set balled-and-burlapped or container stock in the ground in early spring or in fall, while the soil is still cool and moist enough to ease the roots gently into their new home.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant balled-and-burlapped or container stock in early spring or fall.
Hardiness
USDA hardiness zones: 3–7
Temperature: down to -40°C
Troubleshooting
A healthy white fir asks for very little, and most of its troubles trace back to a wet site or a few familiar pests, so there is rarely cause to worry. Keep a friendly eye on the needles and the bark, since that is where the first signs appear. Match what you see below, then act early, while the problem is still small.
Soft white tufts on the bark with puffy, knotted joints
If you spot waxy white fluff settling along the bark and branch joints, take heart, because you have caught the balsam woolly adelgid and you can still help your tree. This little sap feeder slowly knots the joints and stunts fresh growth, so prune away the worst branches, treat with a labeled horticultural oil or systemic, and keep the tree well watered so it has the strength to recover.
Fix:
- Prune out and destroy heavily infested branches
- Apply a labeled horticultural oil or systemic insecticide following the product label and local extension guidance
- Maintain tree vigor with proper watering and avoid drought stress
Fading needles and a thinning canopy after a wet stretch
When the needles lose their color and the canopy starts to thin after a soggy season, the cause is usually Phytophthora or Armillaria root rot quietly at work below the soil. Both settle into wet, packed, or poorly drained ground and rot the roots upward. A tree this far gone cannot be saved, so try not to blame yourself; instead dig at the collar to be sure, fix the drainage, and simply plant your next fir somewhere drier.
Fix:
- Improve site drainage and stop overwatering
- Remove and destroy severely affected trees to limit spread through root grafts
- Avoid replanting firs in the same infected soil
Stippled, bronzed needles with fine webbing in summer heat
A dusty, bronzed cast over the needles during a hot dry spell is the calling card of spruce spider mites, and it is an easy one to handle. They feed when the air turns dry and leave faint webbing among the foliage, so tap a branch over white paper to catch them moving, then give the tree a strong rinse and only reach for a labeled miticide if their numbers stay stubbornly high.
Fix:
- Hose down foliage with a strong stream of water
- Apply horticultural oil or a labeled miticide if populations are high
Spindle-shaped bags swinging from nibbled branches
Those little silken pouches dangling from the twigs are bagworms, each holding a caterpillar that dresses itself in bits of needle as it feeds, and spruce budworm can chew through the new growth the same way. The good news is that hand removal works beautifully, so pick the bags off through winter and early spring, then spray Bacillus thuringiensis while the larvae are still small in late spring.
Fix:
- Handpick and destroy bags in fall through early spring
- Apply Bacillus thuringiensis or a labeled insecticide while larvae are small in late spring
Toxicity
Good news for homes with pets and children: white fir is not toxic. It stands in millions of living rooms each December as a Christmas tree with no risk of poisoning at all. The needles are sharp and resinous, so a big mouthful might unsettle a stomach, but there is no toxin here to lose sleep over.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
You can relax around a curious cat, since a fir carries no toxin for them and a small nibble does no real harm. At most a mouthful of stiff needles brings a little drooling or a brief bout of vomiting, and nothing worse than that.
Dogs None
A dog can chew on fallen needles without any poisoning, because the tree holds nothing toxic. A big helping might unsettle the stomach for a day, but it sorts itself out on its own.
Horses None
You need not worry about horses near a fir, as the foliage is safe and the tree is not among the conifers known to harm them. The needles are sharp and unappealing anyway, so most horses leave it well alone.
Rabbits None
A rabbit that gnaws on bark or needles meets no poison from a true fir. The resinous, prickly foliage rarely tempts them to begin with, so there is little to fret over.
Livestock None
Cattle, goats, and sheep can browse a fir without the abortion risk linked to some other conifers. It makes sound forage, though the sharp needles tend to keep their grazing light.
Birds None
Birds nest and shelter in firs with nothing to fear from the foliage, and many of them feed on the seeds. There is no toxin in the tree to trouble them.
People None
White fir is safe around children, which is exactly why it stands in homes each December as a Christmas tree. The needles are not meant for eating, of course, but a stray one will cause no poisoning.
Needles are not chemically toxic, but ingestion of needles or sap can cause mild mouth and stomach irritation with vomiting or drooling, and large amounts of stiff needles could pose a GI obstruction risk.
Varieties
Most gardens grow the plain species, but a handful of selections are worth knowing for their color, their smaller size, or their place beneath the holiday lights.
Candicans
If you long for color, this selection gives you some of the bluest needles of any white fir, an intense silvery-blue that stays bright all year.
Violacea
Loved for its glaucous blue-gray foliage, this form offers the same lovely color in a slightly gentler tone.
Compacta
A dwarf, slow, irregular form with blue-green needles, this one is a kind choice for a small garden where a full fir would never fit.
Abies fraseri (Fraser fir)
The most popular commercial Christmas tree from the Appalachians, it has short dark-green needles silvered beneath, though it has no patience for heat.
Abies balsamea (balsam fir)
A northern true fir cherished for its strong balsam scent at Christmas, though it struggles in the heat and humidity of the Southeast.
How to propagate
White fir is slow to multiply, so be gentle with yourself about the pace; the method you choose depends on what you want. Seed gives you the true species over several patient years, while grafting keeps the named blue forms faithful to their color.
SeedModerate
Sow stratified seed in spring. · Several years to a sizable sapling
Seed is the usual path, and it simply asks for patience rather than skill, so do not be put off. The seed wants a cold, moist chill before it will wake, and you sow it in spring once that stratification is done. The seedlings rise slowly and dislike dry, hot soil, so a spot in partial shade helps them through their first years, and it takes several seasons for them to reach a sizable sapling.
GraftingDemanding
Late winter under cover. · 1-2 seasons to a viable graft
Named blue forms like Candicans will not come true from seed, so growers graft them onto fir rootstock instead. This is skilled work, done under cover in late winter, so it is fine to leave it to a nursery if you would rather. Once a graft takes, give it one to two seasons to settle and start growing on its own.
Myths
Douglas fir is a true fir, the same as white, Fraser, and balsam fir.
It is easy to assume so, but Douglas-fir belongs to the genus Pseudotsuga and is not a true fir at all. The true firs of the genus Abies stand their seed cones upright on the branch and let them crumble apart right where they sit, and their needles meet the twig by a flat, round base that leaves the bark smooth. Douglas-fir cones hang down, drop whole, and show three-pointed bracts, while spruces leave behind little woody pegs where their needles fall.